Ultrathin porous PtPdCu nanosheets as efficient electrocatalysts for oxygen reduction reaction

Cathode catalysts are vital for proton exchange membrane fuel cells (PEMFCs). However, the sluggish Oxygen reduction reaction (ORR) kinetics and the high cost of platinum-based catalysts collectively pose significant barriers to the large-scale commercialization of PEMFCs. To address these issues, a Pt-Pd-Cu ultrathin nanosheet was prepared with a thickness of about 1.626 nm through chemical synthesis and the substitution method. The synthesis, which involves chemical reduction of Pt precursors followed by directional deposition on the Pd-Cu layer, produces Pt ₃ Pd ₆₄ Cu ₃₃ catalysts with a composite structure that exhibits structural stability and enhanced catalytic performance. Electrochemical tests reveal that the as-synthesized Pt ₃ Pd ₆₄ Cu ₃₃ ultrathin nanosheets show the mass activity (MA) of 1.59 A mg ^-1 _Pt+Pd , and the specific activity (SA) of 0.422 mA cm ^-2 . These performance show 4.42-fold and 1.66-fold enhancements over commercial Pt/C catalysts (MA:0.36 A mg ^-1 _Pt+Pd , SA:0.255 mA cm ^-2 ), respectively. The results demonstrate that the ultrathin nanosheet-structured catalyst enhances catalytic activity, offering a strategy for the design of advanced cathode catalysts.